Hot starting problem (video)

[BlackE30]

Running out of ideas on what the problem is with this, anyone have any ideas?

Before this video, the car was run for roughly 5 minutes. I then let it sit for approx 15 minutes and this is what happened. Basically every time I run into the store or something and come back out I get this problem. If the car is completely cold it will not do this nor will it do it if I start it up a few minutes after shutting it down. It seems to be some kind of priming issue (my guess anyways).

[SamE30e]

FPR vaccum line good?

[BlackE30]

Yea, just checked that the other day, put in a new line that ties it directly to the fitting on the back of the intake manifold.

[BlackE30]

I was reading in the e36 bentley that there is a check valve on the fuel pump, does the stock e30 fuel pump have the same setup?

I just got a fuel pressure checker so I will be doing some troubleshooting with the fuel system to see what I can find.

Jeff

[BlackE30]

Ok, I installed the Fuel pressure guage on the fuel line running to the front of the engine (fuel inlet line to fuel rail) and ran the car for a minute as stated in the bentley. I turned it off, came back 20 minutes later and the pressure was down to 0. So it seems one of the check valves isnt working correctly- either the FPR or the in tank one if there is one down there.

I will check vacuum lines again to make sure but it will have to wait til I get back from a trip on monday.

When the car was running at idle I was getting about 45psi which seems about right for my car since its an s52 with 7psi drop at idle from vacuum.

[jakeb]

FPR

I had the exact same issue with my s52 and I replaced the FPR and it was fixed. Search my threads and you will see all the things that I tried.

If it sat for anything over 15min to 6 hours it would have a hard start. Anything over night or sitting all day and it would start fine. Also if I jumped the fuel relay and let the pump run for 5 seconds it would start every time as well. No matter how long it say. I would try jumping the relay and if it starts right away order a FPR. Or just order a FPR anyway....

[jakeb]

Here is my post...

http://www.r3vlimited.com/board/showthread.php?t=144236

[BlackE30]

Thanks Jake, I remember reading your thread in the past but never saw the solution until now. I will check that out.

Jeff

[BlackE30]

New FPR in, everything seemed good until the car did its usual hot start again!!!!!!!

Next thing to change is the fuel pump check valve I guess. I think I may just get a brand new fuel pump.

[BlackE30]

Just looked up more info on the check valve- Its a 4 dollar part that goes in the fuel line right next to the pump. I think I will save 200 dollars and give this a try first.